1. Technical Field
The present disclosure relates to electrosurgical systems and devices for performing medical procedures. The present disclosure relates to the administration of beneficial agents in general, which include any physiologically, pharmacologically active and/or psychotropic substance(s). More particularly, the present disclosure relates to drug-delivery devices for use with ablation devices and electrosurgical systems including the same.
2. Discussion of Related Art
Electrosurgical instruments have become widely used by surgeons. Electrosurgery involves the application of thermal and/or electrical energy to cut, dissect, ablate, coagulate, cauterize, seal or otherwise treat biological tissue during a surgical procedure. Electrosurgery is typically performed using a handpiece including a surgical instrument (e.g., end effector, ablation probe, or electrode) adapted to transmit energy to a tissue site during electrosurgical procedures, an electrosurgical generator operable to output energy, and a cable assembly operatively connecting the surgical instrument to the generator.
Treatment of certain diseases requires the destruction of malignant tissue growths, e.g., tumors. Electromagnetic radiation can be used to heat and destroy tumor cells. Treatment may involve inserting ablation probes into tissues where cancerous tumors have been identified. Once the probes are positioned, electromagnetic energy is passed through the probes into surrounding tissue.
In the treatment of diseases such as cancer, certain types of tumor cells have been found to denature at elevated temperatures that are slightly lower than temperatures normally injurious to healthy cells. Known treatment methods, such as hyperthermia therapy, heat diseased cells to temperatures above 41° C. while maintaining adjacent healthy cells below the temperature at which irreversible cell destruction occurs. These methods involve applying various forms of energy (e.g., electromagnetic, ultrasonic, etc.) to heat, ablate and/or coagulate tissue. Microwave or radio-frequency energy is sometimes utilized to perform these methods. Radio-frequency (RF) and microwave (MW) energy are electromagnetic radiation in the frequency ranges of 3 kilohertz (kHz) to 300 Megahertz (MHz), and 300 MHz to 300 gigahertz (GHz), respectively. Other procedures utilizing electromagnetic radiation to heat tissue also include coagulation, cutting and/or ablation of tissue.
Electrosurgical devices utilizing electromagnetic radiation have been developed for a variety of uses and applications. A number of devices are available that can be used to provide high bursts of energy for short periods of time to achieve cutting and coagulative effects on various tissues. There are a number of different types of apparatus that can be used to perform ablation procedures. Typically, microwave apparatus for use in ablation procedures include a microwave generator that functions as an energy source, and a microwave surgical instrument (e.g., microwave ablation probe) having an antenna assembly for directing the energy to the target tissue. The microwave generator and surgical instrument are typically operatively coupled by a cable assembly having a plurality of conductors for transmitting microwave energy from the generator to the instrument, and for communicating control, feedback and identification signals between the instrument and the generator.
The basic purpose of both monopolar and bipolar electrosurgery is to produce heat to achieve the desired tissue/clinical effect. In monopolar electrosurgery, devices use an instrument with a single, active electrode to deliver energy from an electrosurgical generator to tissue, and a patient return electrode (usually a plate positioned on the patient's thigh or back) as the means to complete the electrical circuit between the electrosurgical generator and the patient. In bipolar electrosurgery, the electrosurgical device includes two electrodes that are located in proximity to one another for the application of current between their surfaces. Bipolar electrosurgical current travels from one electrode, through the intervening tissue to the other electrode to complete the electrical circuit.
The benefits provided by controlled delivery of active agents for the treatment of injury or disease are well recognized in the art and various approaches have been taken to realize the goal of delivering active agents at desired rates over predetermined periods of time. Various different implantable controlled delivery formulations are known in the art, and various different mechanisms have been employed for delivering active agent from implantable formulations at a controlled rate over time.
Medical imaging has become a significant component in the clinical setting and in basic physiology and biology research, e.g., due to enhanced spatial resolution, accuracy and contrast mechanisms that have been made widely available. Medical imaging now incorporates a wide variety of modalities, e.g., computed tomography (CT) and magnetic resonance imaging (MRI), that noninvasively capture the structure and/or function of the human body. Such images are acquired and used in many different ways including medical images for diagnosis, staging and therapeutic management of malignant disease.
Medical image processing, analysis and visualization play an increasingly useful role in disease diagnosis and monitoring as well as, among other things, surgical planning and monitoring of therapeutic procedures. A contrast agent may be used for enhancement of the contrast of structures or fluids within the body (or region of interest) in medical imaging to allow visualization and evaluation of lesions seen minimally, if at all, with imaging alone. There is a continuing need for devices capable of dispensing a contrast agent to enhance the visualization of the lesion during the procedure.
Despite advancements in the use of electrosurgical devices for treating biological tissue, there are still concerns for tumor reoccurrence. A continuing need exists for devices capable of dispensing a controlled delivery formulation of a desired active agent, which may help to reduce or eliminate tumor reoccurrence.